We suggest looking for accommodation options on booking.com or airbnb.
The area around the conference venue,
Largo S. Marcellino 10 - Napoli (https://goo.gl/maps/psF5P1kujB4QUeoPA)
is a reasonable area to search for accommodations. It is in the historical city centre, it is easy to walk around, find restaurants, bars and other facilities.
In case you want to find accommodation further away, take into account that the venue is 5 mins walk (400 meters) from the Line 1 subway station “Duomo”, or 15 mins walk from the Line 2 subway station "Montesanto".